:root {
  --bg: #ffffff;
  --bg-soft: #f5f6fb;
  --card: #ffffff;
  --text: #14162b;
  --muted: #5d6280;
  --line: #e4e6f0;
  --accent: #5b4bff;
  --accent-2: #00b3a4;
  --accent-text: #ffffff;
  --shadow: 0 10px 30px rgba(20, 22, 43, .08);
  --radius: 18px;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d0f1c;
    --bg-soft: #141729;
    --card: #181b30;
    --text: #eef0ff;
    --muted: #a3a8c7;
    --line: #2a2e4a;
    --accent: #7c6fff;
    --accent-2: #2fd3c4;
    --shadow: 0 10px 30px rgba(0, 0, 0, .35);
  }
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: Inter, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--accent); text-decoration: none; }
.wrap { max-width: 1120px; margin: 0 auto; padding: 0 20px; }

/* Header */
header.top {
  position: sticky; top: 0; z-index: 10;
  background: color-mix(in srgb, var(--bg) 85%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
header.top .wrap { display: flex; align-items: center; justify-content: space-between; height: 64px; gap: 16px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 800; font-size: 19px; color: var(--text); letter-spacing: .3px; }
.brand img { width: 32px; height: 32px; }
nav.links { display: flex; gap: 22px; align-items: center; }
nav.links a.plain { color: var(--muted); font-weight: 500; }
nav.links a.plain:hover { color: var(--text); }
@media (max-width: 640px) { nav.links a.plain { display: none; } }

/* Buttons */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 12px 22px; border-radius: 12px; border: 1px solid transparent;
  font: inherit; font-weight: 600; cursor: pointer; transition: transform .15s, box-shadow .15s, background .15s;
}
.btn:hover { transform: translateY(-1px); }
.btn.primary { background: var(--accent); color: var(--accent-text); box-shadow: 0 8px 20px color-mix(in srgb, var(--accent) 35%, transparent); }
.btn.ghost { background: transparent; color: var(--text); border-color: var(--line); }
.btn.small { padding: 8px 16px; font-size: 14px; }
.btn.block { width: 100%; }
.btn:disabled { opacity: .6; cursor: wait; transform: none; }

/* Hero */
.hero { padding: 84px 0 64px; text-align: center; position: relative; overflow: hidden; }
.hero::before {
  content: ""; position: absolute; inset: -40% -10% auto; height: 520px; z-index: -1;
  background: radial-gradient(closest-side, color-mix(in srgb, var(--accent) 22%, transparent), transparent),
              radial-gradient(closest-side at 70% 60%, color-mix(in srgb, var(--accent-2) 18%, transparent), transparent);
}
.pill { display: inline-block; padding: 6px 14px; border-radius: 999px; background: var(--bg-soft); border: 1px solid var(--line); color: var(--muted); font-size: 14px; margin-bottom: 22px; }
.hero h1 { font-size: clamp(34px, 6vw, 60px); line-height: 1.08; margin: 0 0 18px; letter-spacing: -1px; }
.hero h1 span { white-space: nowrap; background: linear-gradient(90deg, var(--accent), var(--accent-2)); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero p.lead { font-size: clamp(17px, 2.2vw, 20px); color: var(--muted); max-width: 680px; margin: 0 auto 32px; }
.hero .cta { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }
.hero small { display: block; margin-top: 14px; color: var(--muted); }

/* Chat demo */
.demo { max-width: 720px; margin: 54px auto 0; background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); text-align: left; padding: 20px; }
.msg { padding: 12px 16px; border-radius: 14px; margin: 8px 0; max-width: 88%; }
.msg.user { background: var(--accent); color: var(--accent-text); margin-left: auto; border-bottom-right-radius: 4px; }
.msg.ai { background: var(--bg-soft); border-bottom-left-radius: 4px; }
.msg.ai b { color: var(--accent); }

/* Sections */
section { padding: 72px 0; }
section.soft { background: var(--bg-soft); }
h2 { font-size: clamp(28px, 4vw, 40px); margin: 0 0 12px; text-align: center; letter-spacing: -.5px; }
p.sub { text-align: center; color: var(--muted); margin: 0 auto 44px; max-width: 620px; }

.grid { display: grid; gap: 18px; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
.card { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; }
.card .ico { font-size: 28px; margin-bottom: 10px; }
.card h3 { margin: 0 0 6px; font-size: 18px; }
.card p { margin: 0; color: var(--muted); }

.steps { counter-reset: s; }
.steps .card { position: relative; padding-top: 56px; }
.steps .card::before { counter-increment: s; content: counter(s); position: absolute; top: 18px; left: 24px; width: 30px; height: 30px; border-radius: 50%; background: var(--accent); color: #fff; display: grid; place-items: center; font-weight: 700; }

/* Tariffs */
.plans { display: grid; gap: 18px; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); align-items: stretch; }
.plan { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 28px; display: flex; flex-direction: column; position: relative; }
.plan.popular { border: 2px solid var(--accent); box-shadow: var(--shadow); }
.plan .badge { position: absolute; top: -12px; right: 20px; background: var(--accent); color: #fff; font-size: 12px; font-weight: 700; padding: 4px 10px; border-radius: 999px; }
.plan h3 { margin: 0; font-size: 20px; }
.plan .price { font-size: 40px; font-weight: 800; margin: 10px 0 2px; }
.plan .price small { font-size: 16px; color: var(--muted); font-weight: 500; }
.plan ul { list-style: none; padding: 0; margin: 18px 0 24px; flex: 1; }
.plan li { padding: 6px 0 6px 26px; position: relative; color: var(--muted); }
.plan li::before { content: "✓"; position: absolute; left: 0; color: var(--accent-2); font-weight: 800; }

/* FAQ */
details { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 16px 20px; margin-bottom: 10px; }
details summary { cursor: pointer; font-weight: 600; list-style: none; }
details summary::-webkit-details-marker { display: none; }
details summary::after { content: "+"; float: right; color: var(--muted); }
details[open] summary::after { content: "−"; }
details p { color: var(--muted); margin: 10px 0 0; }
.faq { max-width: 780px; margin: 0 auto; }

/* Footer */
footer { border-top: 1px solid var(--line); padding: 36px 0; color: var(--muted); font-size: 14px; }
footer .wrap { display: flex; flex-wrap: wrap; gap: 16px 32px; justify-content: space-between; }
footer a { color: var(--muted); }
footer a:hover { color: var(--text); }

/* Modal */
.modal { position: fixed; inset: 0; background: rgba(8, 9, 20, .55); display: none; align-items: center; justify-content: center; padding: 16px; z-index: 50; }
.modal.open { display: flex; }
.modal .box { background: var(--card); border-radius: var(--radius); padding: 28px; width: 100%; max-width: 420px; box-shadow: var(--shadow); border: 1px solid var(--line); }
.modal h3 { margin: 0 0 6px; }
.modal p { color: var(--muted); margin: 0 0 18px; }
.modal label { font-size: 14px; font-weight: 600; display: block; margin-bottom: 6px; }
.modal input[type=email] { width: 100%; padding: 12px 14px; border-radius: 12px; border: 1px solid var(--line); background: var(--bg); color: var(--text); font: inherit; margin-bottom: 14px; }
.modal .agree { display: flex; gap: 8px; font-size: 13px; color: var(--muted); margin-bottom: 16px; align-items: flex-start; }
.modal .err { color: #e5484d; font-size: 14px; min-height: 20px; margin-bottom: 8px; }
.modal .row { display: flex; gap: 10px; }

/* Legal pages */
.doc { max-width: 820px; margin: 0 auto; padding: 48px 20px 80px; }
.doc h1 { font-size: 32px; }
.doc h2 { text-align: left; font-size: 22px; margin-top: 32px; }
.doc p, .doc li { color: var(--text); }
.doc .note { background: var(--bg-soft); border: 1px dashed var(--line); padding: 14px 18px; border-radius: 12px; color: var(--muted); }
.center-page { min-height: 70vh; display: grid; place-items: center; text-align: center; padding: 40px 20px; }
.center-page .card { max-width: 480px; }